XRay XB4 '19 Project

Rc racing.  I don't do it, and I don't really care about it.  If you read RC magazines and product advertisements though, you'd think it was the only thing in the world that mattered and the only thing on which RC enthusiasts spend their money.  And they certainly do spend money.  Every single product is advertised to decrease lap times and improve performance, even when one product does the opposite thing to your car as another.  You'll hear claims that shaving grams off this or that is noticeable, that using less paint or shorter wires makes your car faster, or that a 0.5mm difference in shock rebound left to right will change how your car corners.  While all technically true, it is also all rubbish.  As an engineer I know that these changes are way down past any reasonable number of significant figures.  That's not to say that there aren't big differences between cars though, and a car purpose built for racing is likely to handle much better than one that isn't.  It was with that in mind that I turned to XRay to see what all the fuss was about.  A group of like minded co-workers and I, too incompetent to compete against anyone else, decided we should form our own low skill racing league.

Once I decided I wanted to try a real racing buggy, there were a few decisions to be made.  The first was scale.  1/8 buggy is apparently the most prestigious, but in the past I've found that 1/8 scale requires a lot of space to run so I tend to prefer 1/10.  There is no reason 1/10 needs to be any slower with an appropriate power system,and at that scale I can drive in my yard or the road in front of my house.  The smaller scale is also considerably less expensive to build and maintain.  Next decision was 2WD versus 4WD.  The other members of The League were in favor of 4WD for no particular reason, and I saw no reason to argue.  Finally, what about brand?  I knew just enough racing to be aware of some of the most common brands: Associated, Losi, Schumacher, XRay, Mugen Seiki, Kyosho, Tekno, and Serpent.  I think the decision to choose XRay came mainly from the desire to try a European brand and also because the 2019 model XB4 was for sale at clearance prices.

Model chosen, we next needed to decide on League sanctioned electronics.  A racing kit doesn't come with any electronics, and doesn't come with tires either.  Having no bylaws really makes things open.  We picked the Hobbywing Xerun system at 5900kV (5.5T) and decided that, rather than being banned from using driving aids, AVC was required.

This is a 4WD, shaft driven buggy with double wishbone suspension and aluminum big bore shocks.  The main chassis tray is aluminum and uses carbon fiber stiffeners and shock towers.  The amount of adjustability is truly mind boggling and is explained in detail in the attached build record.  With a set of Proline Inversion tires, this thing is pure joy to drive.  The speed is incredible, the control precise, and the handling marvelous.  Whether or not it was worth the cost is obviously a matter of some subjectivity.  Is it twice as fun as a slower, less capable buggy?  Probably not.  The cost is based on pursuit of the lowest possible lap time.  Low lap times are predicated on not crashing, so I still have some work to do.

Update:  This model was destroyed in the 2022 fire.  It has not been replaced.